Flying shear control



13, 1940- H. G. R. BENNETT 2,211,362

FLYING SHEAR CONTROL Filed Dec. 10, 1936 J INVENTOR. HERBERT d E. BENNETZ HIS A TTORNEYS.

Patented Aug. 13, 1940 UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to flying shears, one of the objects being to provide a control for a shear of this type whereby the shear may be used to cut predetermined lengths from the advancing 5 end of traveling work, and whereby the amounts cut from these ends may be varied at will.

The accompanying drawing schematically illustrates the invention as applied to a flying shear arranged on the exit side of a billet mill, in of which only the finishing stand is shown.

The flying shear I is fixedly positioned in spaced relation with respect to the finishing rolls 2 of the mill, and a roller table 3 carries the work from the mill through and beyond the 15 shear I.

relatively high speed.

Some shears are powered by an electric motor and some are steam-actuated. The shear I is of the latter type, and is controlled by a steam pilot-valve 4. This valve is provided with an electro-magnetic thrustor 5 arranged 'so that energization of its solenoid eflects starting of 39 lines 6 and I through the contacts 8 of a time delay relay, by way of a circuit 9. This relay includes a main solenoid III that is energized by the lines 6 and 'I through a circuit II when the contacts I2 of a flag switch are closed, this flag switch being fixedly positioned in the-path of work leaving the rolls 2 and advancing toward the shear I. The normally closed contacts of this flag switch are opened when the switchs contact-operating device is engaged by work 40 traveling over the table 3, this causing deenergization of the solenoid I and subsequent closing of the contacts 8, with consequent energization of the solenoid of the thrustor whereby the shear-I is started.

45 The time delay relay is of the type depending on the gradual decay of the magnetic flux created by the solenoid I 0 and which holds open spring-closed contacts, which are those numbered 8, this decay period allowing time for the 0 work to travel into cutting association with the shear I. The period of time required for the ,decay of the magnetic flux may be influenced by a neutralizing solenoid l3, energized by the lines 6 and I through a circuit I4 which includes 55 a rheostat I5. Adjustment of the rheostat I5 In many instances the work travels at varies the time delay of the relay, an increase in the current through the neutralizing solenoid I3 shortening the time and a decrease lengthening the time. Thereiore, to cut any desired amount from the advancing end of the work 5 it is only necessary to adjust the rheostat I5 so as to delay the closing of the contacts -8 the period of time proper to permit the desired amount of the advancing end of the work to travel through the shear I.

Since this work is leaving a rolling mill, its traveling speed may vary, and if its speed varies it will be impossible to predetermineexactly the interval of time during which the contacts 8 should remain open after opening of the contacts I2 by the advancing end of the work. To overcome this difliculty one of the finishing rolls 2 is arranged to drive an electric tachometer I6, which is simply a generator whose voltage output varies in proportion to the speed with go which it is driven. This tachometer is connected to a graphic voltmeter I 'I- by lines I8, and the indicating element of this meter is coupled to the moving contactor I 5 of the rheostat I5 by way of shafts I9 interconnected by a clutch g5 having a lever 20 for disengaging it when desired.

The above arrangement renders the setting of the rheostat I5 responsive to the speed of the finishing rolls 2 of the mill, and consequently also responsive to the speed with which the work is advancing toward the shear I. There- 'fore, it is possible to accurately predetermine the amount 01' the advancing end of the work to be cut by the shear I, regardless of the travel- 5 ing speed of the work. Different amounts may be cut by manually setting the moving contactor I5 of the rheostat, which is possible when the clutch 2B is disengaged. Upon engagement of the clutch 20, automatic speed compensation results. In its practical form, the rheostat may be provided with an external indicator calibrated in terms of the length to be cutfrom the advancing 'end of the work, a segment 01. this indicator being indicated at I 5.

I claim: a

1. The combination of arflying shear, elec trically powered starting means for said shear,

a time delay relay, a circuit for connecting said means to a current supply through the contacts 5 tion and said combination including current control means responsive to the speed the work is advancing toward said shear, and a circuit for connecting said adjusting means to a current supply through said control means.

2. The combination of a flying shear, electrically powered starting means for said shear, a. time delay relay, a circuit for connecting said means to a current supply through the contacts 10 of said relay, a work operated switch in front of said shear, a circuit for connecting the solenoid of said relay to a current supply through HERBERT G. R. BENNETT. 

